Recovery of Niobium and Tantalum by Solvent Extraction from Penouta Sn–Ta–Nb Deposit

This work presented data using always real solutions yielded from the treatment of Spanish raw material, in detail, from a slag obtained in a pyrometallurgy process of tin production from mining tailings containing mainly cassiterite and columbo tantalite. In this investigation the raw material was treated by acid leaching, using HF/H2SO4 as a leaching agent. Then, liquid-liquid extraction of Nb and Ta have performed with Cyanex®923 extractant, further, both metals were separately stripped. Once metals were separated into two aqueous solutions, they were precipitated and calcined to yield the corresponding compounds (Nb2O5 of 98.5% purity and Ta2O5 of 97.3% purity).